Type of decoration involving the application of gold. The oldest technique for gilding is called "best gilding", "solid gilding" or "fire gilding". Pure gold is mixed with mercury to a liquid, applied to the piece to be gilded and than fired at about 730 centigrade to leave pure gold. The gold is dull in appearance when it comes from the kiln and needs to be burnished to produce a bright finish.
In her book 'Gilded Dragons' Carol Michaelson refers to this method as "Mercury amalgam gilding" and tells it is done by mixing gold with mercury and applying the resultant amalgam to a metal object. When heated the free mercury boils off and the gold remains on the surface as a matt plating layer. Mercury gilding was not developed until the Warring States period.
Another method introduced in the west in the 1850's is "liquid gold" where powdered gold is applied as a liquid suspension and is painted onto the pieces. When it comes from the kiln, the gold is already bright and needs no burnishing. The drawback of this method is that bright gold tends to rub off very easily.
According to Pere d'Entrecolle, a Jesuit missionary reporting from the city of Jingdezhen in 1712 and 1722, gilding on Chinese porcelain was introduced "early in the Qing dynasty" and was done by grinding leaf gold to a powder and mixing this with an ordinary colorless lead enamel.
It is also obvious from extant Chinese porcelain pieces, that during early 20th century it is introduced a new method of gilding, which is different from earlier methods, since it gives a high gloss shiny and metalic impression, different from the older lead glaze gilding. This method or material is likely to be the same as is still the prevalent in modern porcelain industries.